Since the hydrological cycle of the Himalayan region is becoming increasingly unpredictable as a result of global warming, many of the hydropower plants are already producing less than their capacity today-- due to extremely reduced water flow in the rivers-and these power stations might become defunct altogether if the current weather trends continue along their unpredictable paths. [break]
The data of this winter´s hydropower output sheds some light on what can happen when climates go awry. According to Sher Singh Bhat, Director of Nepal Electricity Authority (NEA), while the dependable capacity of the run-off-the-river hydropower plants is about 525 megawatts, this winter, the plants only generated 180 megawatts: that´s just one third of their capacity.
Nepal´s only storage hydroelectricity plant, the Kulekhani project, reached new lows this year. Lows as in, this year, its reservoirs stored the lowest amount of water in its history. In other years, the Kulekhani reservoir used to be filled to the brim by October, but this year, the water level was 20 meters less than its full capacity. The reason?
“It´s obvious, isn´t it?” says Bhat. “It didn´t rain much, and the catchment area of the reservoir came up empty.”
But how obvious is the cause-and-effect link between global warming and the droughts that Nepal was afflicted with this year? Climate change experts can´t “claim” that this year´s drought was caused by global warming only because doing so would goad the opponents of the climate-change theory to pile on infantile comebacks.
But they do say that the massive change in the hydrological cycle worldwide is a direct result of global warming whereby extreme weather conditions such as this year´s have not just become more frequent but also more severe. Ajaya Dixit of the institute for Social and Environmental Transition-Nepal, for example, says that the rain patterns will get more erratic. In the face of such prognosis, building more hydropower plants in Nepal might not seem like the best idea.
Dixit says the erratic rainfall will affect the hydropower plants in three major ways: First, extended dry periods such as this winter´s will reduce water flow, thereby severely reducing the capacity of the run-off-the-river projects. The next two effects have to do with floods. Climate change also means an increase in the number of water-related disasters and thus power plants, which will be first in line should disaster strike, are the most prone to damage. And finally, flash floods can also clog up the reservoirs with sediments and reduce their water-holding capacities.
“The whole case for constructing huge hydropower plants rests on the assumption that climate is constant; but that assumption has been disproved many times over now. Thus if we are to draw conclusions from the more solid assumption--that climate has changed and will continue to change--we can only conclude that our existing power plants will not just produce a lot less energy than their capacity but will also face much greater risk from environmental disasters,” says Dixit.
So how can Nepal find the solution to its power woes?
By thinking outside the lines that the power sector has been boxed in. Dixit feels it´s a better idea to expand Nepal´s energy sources rather than to rely solely on hydroelectricity for the country´s energy needs.
“We must think wind and solar too,” says Dixit.
kushal@myrepublica.com
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